S.A. Shakhova
Absolutely Closed Groups in the Quasi-varieties of Nilpotent Groups of Class at Most Two
We assume that Hprs, Hp are the groups with the following presentations in the variety of nilpotent groups of class at most two: Hprs = gr(x, y || xp′ = yp′ = [x, y]p = 1), Hp = gr(x, y || [x, y]p = 1),where p is a prime number, r, s are natural numbers. It is proved that the group Hprs is an absolutely closed group in the quasi-variety qHprs, and any divisible group belonging to the quasi-variety qHp is an absolutely closed group in the quasi-variety qHp.
Key words: quasi-variety, absolutely closed group, dominion, group.